A pTalpha-negative subpopulation of CD25+ TN thymocytes revealed by a transgenic marker

We have recently generated 5'lambda5-huTAC mice, which express the human CD25 (huTAC) gene under the control of the 5'-flanking region of the mouse lambda5-gene. The huTAC-transgene was expressed in pre-B cells but neither in mature B cells nor in T cells of these mice. In this report we demonstrate that the transgene is also transiently expressed by adult CD25+ CD3-CD4-CD8- (triple negative, TN) thymocytes and in fetal thymocytes. The huTAC+, in contrast to the huTAC- subpopulation of the CD44+CD25+ TN cells, was unexpectedly found not to express the pTalpha-gene. Still the huTAC+CD44+CD25+ TN cells reconstituted the development of both alphabeta and gammadelta lineage cells equally efficiently as the pTalpha-expressing huTAC- fraction, demonstrating that this pTalpha-negative subpopulation contained precursors for both T-cell lineages. Single cell reverse transcription-polymerase chain reaction (RT-PCR) experiments demonstrated that also in normal mice only a fraction of CD44+CD25+ and CD44-CD25+ TN cells expressed this gene. Taken together, these data indicate that huTAC transgene expression revealed a truly pTalpha-negative fraction of the CD44+CD25+ TN cells. The observation that not all precursors in the CD25+ TN population express the pTalpha-gene has important implications for the understanding of early T-cell development and T-cell lineage commitment.

Counseling Hypertensive patients: an observational study of 21 public health nurses

This study observed the public health nurse's and the patient's activity level during blood pressure measurement and the kind of nonpharmacological treatment that was given. Using the Nurse Practitioner Rating Form, three structured observations were made of 21 public health nurses at their offices at health care centers. The nurses were randomly selected from 22 health care centers in Southern Sweden. The public health nurses used nonpharmacological treatment at 18 out of 63 visits, mainly diet and physical activity. The nonpharmacological conversation had a psychosocial aspect at 15 observations. During the visits, most of the facts and advice concerned somatic aspects of health promotion. Almost all patients were asked about their medication. At more than half of the observations, the nurses and the patients met at the same medium or high communication level. The nurses need training and information about nonpharmacological treatment to practice health promotion in hypertension care.

Low incidence of toxoplasma infection during pregnancy and in newborns in Sweden

To estimate the burden of disease due to congenital toxoplasmosis in Sweden the incidence of primary infections during pregnancy and birth prevalence of congenital toxoplasmosis in 40,978 children born in two regions in Sweden was determined. Women possibly infected during pregnancy were identified based on: 1, detection of specific IgG based on neonatal screening of the phenylketonuria (PKU) card blood spot followed by retrospective testing of stored prenatal samples to detect women who acquired infection during pregnancy and follow up of their children to 12 months: 2, detection of specific IgM on the PKU blood spot. The birth prevalence of congenital toxoplasmosis was 0.73/10,000 (95 % CI 0.15-2.14) (3/40,978). The incidence of primary infection during pregnancy was 5.1/10,000 (95% CI 2.6-8.9) susceptible pregnant women. The seroprevalence in the southern part was 25.7% and in the Stockholm area 14.0%. The incidence of infection during pregnancy was low, as the birth prevalence of congenital toxoplasmosis. Neonatal screening warrants consideration in view of the low cost and feasibility.

[Residential care after the geriatric care reform. District nurses experience extensive responsibility and limited rights]

We studied the care of patients in homes for the elderly and in special homes for the demented in the city of Malmö. Nine district nurses were interviewed using a tape recorder, and the content of the interviews was analyzed. Many patients needed extensive care, and resources were insufficient regarding both number of staff and their competence. The management of nursing in the various districts of the city was not well-defined. More consulting time was requested on the part of both district nurses and general practitioners in homes for the elderly and homes for the demented.

Early TCR αβ Expression Promotes Maturation of T Cells Expressing FcεRIγ Containing TCR/CD3 Complexes

In a previous study we presented data indicating that the expanded population of CD4(-)CD8(-) (DN) alphabeta T cells in TCRalpha-chain-transgenic mice was partially if not entirely derived from gammadelta T cell lineage cells. The development of both gammadelta T cells and DN alphabeta T cells is poorly understood; therefore, we thought it would be important to identify the immediate precursors of the transgene-induced DN alphabeta T cells. We have in this report studied the early T cell development in these mice and we show that the transgenic TCRalpha-chain is expressed by precursor thymocytes already at the CD3(-)CD4(-)CD8(-) (triple negative, TN) CD44(+)CD25(-) stage of development. Both by using purified precursor populations in reconstitution experiments and by analyzing fetal thymocyte development, we demonstrated that early TN precursors expressing endogenous TCRbeta-chains matured into DN alphabeta T cells at several stages of development. The genes encoding the gamma-chain of the high affinity receptor for IgE (FcepsilonRIgamma) and the CD3zeta protein were found to be reciprocally expressed in TN thymocytes such that during development the FcepsilonRIgamma expression decreased whereas CD3zeta expression increased. Furthermore, in a fraction of the transgene-induced DN alphabeta T cells the FcepsilonRIgamma protein colocalized with the TCR/CD3 complex. These data suggest that similarly to gammadelta T cells and NKT cells, precursors expressing the TCR early in the common alphabetagammadelta developmental pathway may use the FcepsilonRIgamma protein as a signaling component of the TCR/CD3 complex.

Frequency of human parvovirus B19 infection in intrauterine fetal death

BACKGROUND

Parvovirus B19 is known to cause fetal death in the second trimester, mainly in combination with hydrops fetalis. However, the frequency of parvovirus-B19-associated non-hydropic fetal loss in the late second and third trimester has not been thoroughly investigated. We aimed to investigate the frequency of parvovirus B19 infection in unselected cases of intrauterine fetal death and to assess the sensitivity of different diagnostic procedures.

METHODS

Of 14147 deliveries in three hospitals in the major Stockholm area of Sweden, all cases of intrauterine fetal death (>22 gestational weeks) that occurred between January, 1998, and May, 1999 (n=47), referred cases of miscarriage (<22 gestational weeks, n=37), and induced abortions (n=29), were included in the study. Placental and fetal tissues were examined by means of parvovirus-B19-specific PCR, histopathology, and immunohistochemistry. Placental tissues from 53 normal pregnancies at term were also examined.

FINDINGS

Significantly more cases of intrauterine fetal death were positive for parvovirus B19 DNA (seven [15%]) than were normal pregnancies at term (zero, p=0.049). Furthermore, parvovirus B19 DNA was found in two (5%) of the miscarriages but not in any of the cases of induced abortion. Only three of nine DNA-positive cases had parvovirus-B19-associated inclusions and stained positive for viral proteins. All but one of the DNA-positive cases of intrauterine fetal death were non-hydropic.

INTERPRETATION

The presence of parvovirus B19 DNA in cases of late second-trimester and third-trimester fetal death is common, and most are non-hydropic. The sensitivity of conventional diagnostic procedures for intrauterine fetal death could be greatly improved by addition of parvovirus B19 PCR.

Blood pressure measurement--an observational study of 21 public health nurses

The purpose of this study was to observe how public health nurses perform blood pressure measurement. Structured observations were made of 21 randomly selected public health nurses while they performed three blood pressure measurements. The public health nurses used an overall correct method for blood pressure measurement. Five nurses out of 21 used the Tri-cuff but the soft cuff was most frequently used. When choosing the breadth of the cuff, 10 nurses decided by eye and not by the marks on the cuff. To ensure a completely correct method additional information is needed by nurses.

Nurses' first encounters with parents of new-born children--public health nurses' views of a good meeting

The nurse's view of the first meeting with parents of new-born children ma have consequences for the quality of future contact. A good start will lay a soli foundation for a lasting relationship, and have an affect on the nurse's work to support parents and children and to promote health. We do not know wha nurses mean by a 'good meeting'. The aim of this study was to discover how nurses view the first meeting as a general preventive measure aimed at all parents and their new-born children. Four focus groups interviews were held with nurses from different primary health care areas in the county of Skåne, southernmost Sweden. Analysis of the content in the transcribed interview texts disclosed eight subcategories: good contact/reciprocal relationship; willingness to listen; guest/ equal roles; time/peace and quiet; the family in its environment; socio-cultural aspects; confirmation/support; and individual advice. Three categories were established: creating trust; creating a supportive climate; and creating a picture of the family's life situation. The home visit was seen as an important way to establish trust and obtain a picture of the family's life situation, which was in turn essential for creating a supportive climate.

Seroprevalence of Toxoplasma gondii among pregnant women in Sweden

BACKGROUND

Primary infection with Toxoplasma gondii during pregnancy can cause fetal infection with a risk of complications for the fetus. The proportion of women at risk of acquiring the infection during pregnancy in Sweden is not known.

METHODS

The seroprevalence of Toxoplasma gondii among pregnant women in Sweden was calculated when 40,978 blood samples collected on filter paper eluates from newborns were tested for Toxoplasma specific immunoglobulin G. The newborns in two geographically different areas (Stockholm County and Skåne County) were investigated during a 16-month period between April 1997 and July 1998. The anti-toxoplasma IgG antibodies detected in the eluates were considered to be of maternal origin and to reflect the immune status of the mother.

RESULTS

The seroprevalence was 14.0% in Stockholm County and 25.7% in Skåne County. The seroprevalence among women born in the Nordic countries was 11.1% in Stockholm and 24.9% in Skåne. The corresponding figures for women born outside the Nordic countries were 24.3% and 29.4%. On comparing the seroprevalence found in this study with older data, the overall seroprevalence in pregnant women born in the Nordic countries and living in Stockholm was found to have decreased between 1969 and 1998. The seroprevalence in different birth cohorts, longitudinally followed in the previous and the present studies, remained at the same level over 20 years despite the increasing age of the women.

CONCLUSION

These results suggest that the majority of seropositive pregnant women in Sweden today have seroconverted before entering the childbearing period and that the percentage of women in Sweden acquiring toxoplasmosis during the childbearing period is low.

The crystal structure of staphylococcal enterotoxin H: implications for binding properties to MHC class II and TcR molecules

The X-ray structure of the superantigen staphylococcal enterotoxin H (SEH) has been determined at 1.69 A resolution. In this paper we present two structures of zinc-free SEH (apoSEH) and one zinc-loaded form of SEH (ZnSEH). SEH exhibits the conventional superantigen (SAg) fold with two characteristic domains. In ZnSEH one zinc ion per SEH molecule is bound to the C-terminal beta-sheet in the region implicated for major histocompatibility complex class II (MHC class II) binding in SEA, SED and SEE. Surprisingly, the zinc ion has only two ligating amino acid residues His206 and Asp208. The other ligands to the zinc ion are two water molecules. An extensive packing interaction between two symmetry-related molecules in the crystal, 834 A(2)/molecule, forms a cavity that buries the zinc ions of the molecules. This dimer-like interaction is found in two crystal forms. Nevertheless, zinc-dependent dimerisation is not observed in solution, as seen in the case of SED. A unique feature of SEH as compared to other staphylococcal enterotoxins is a large negatively charged surface close to the Zn(2+) site. The interaction of SEH with MHC class II is the strongest known among the staphylococcal enterotoxins. However, SEH seems to lack a SEB-like MHC class II binding site, since the side-chain properties of structurally equivalent amino acid residues in SEH and those in SEB-binding MHC class II differ dramatically. There is also a structural flexibility between the domains of SEH. The domains of two apoSEH structures are related by a 5 degrees rotation leading to at most 3 A difference in C(alpha) positions. Since the T-cell receptor probably interacts with both domains, SEH by this rotation may modulate its binding to different TcR Vbeta-chains.

Evaluation of the ability of thermal and electrical tests to register pulp vitality

The aim of the present study was to evaluate the ability of thermal and electrical tests to register pulp vitality. Sensitivity, specificity, negative predictive value and positive predictive value were calculated by comparing the test results with a "gold standard". The thermal tests studied were a cold test (ethyl chloride) and a heat test (hot gutta-percha). For the electrical test, the Analytic Technology Pulp Tester was used. The examined teeth were 59 teeth with unknown pulpal status in need of endodontic treatment and 16 intact teeth, all with radiographically normal periapical bone structures. In total 46 teeth with vital pulps and 29 teeth with necrotic pulps were tested. This gave a disease prevalence of 39%. The gold standard was established by direct pulp inspection of the 59 teeth in need of endodontic treatment. In the 16 intact teeth the pulp was judged as vital. The number of true positive (TP), false positive (FP), true negative (TN) and false negative (FN) test results was calculated for each method as compared to the gold standard. Based on this, the sensitivity, specificity, positive predictive value and negative predictive value were calculated for each method. The sensitivity was 0.83 for the cold test, 0.86 for the heat test and 0.72 for the electrical test. The specificity was 0.93 for the cold test, 0.41 for the heat test and 0.93 for the electrical test. The positive predictive value was 0.89 for the cold test, 0.48 for the heat test and 0.88 for the electrical test, and the negative predictive value was 0.90 for the cold test, 0.83 for the heat test and 0.84 for the electrical test. This indicated that the probability of a non-sensitive reaction representing a necrotic pulp was 89% with the cold test, 48% with the heat test and 88% with the electrical test. It also indicated that the probability of a sensitive reaction representing a vital pulp was 90% with the cold test, 83% with the heat test and 84% with the electrical test.

Three children with congenital toxoplasmosis: early report from a Swedish prospective screening study

The aim of this prospective study was to define the incidence of congenital toxoplasmosis in Sweden. Blood eluates collected on filter papers, Guthrie cards, from 40978 newborn babies were analysed for specific immunoglobulin M (IgM) and IgG antitoxoplasma antibodies. This is a preliminary report of three children with congenital toxoplasmosis, defined by the occurrence of antitoxoplasma-specific IgM antibodies. Two children were asymptomatic at birth. They were both normally developed at the age of 12 and 15 months, respectively. The third child had unidentified but uncomplicated symptoms of infection in the neonatal period. As a result of the screening congenital toxoplasmosis was confirmed and treatment instituted. Microphthalmus and peripheral chorioretinitis were detected in one eye. In spite of the chemotherapeutic treatment he developed hydrocephalus needing neurosurgical intervention at the age of 3 months. His development at 14 months was normal. The incidence in Sweden of congenital toxoplasmosis detected by specific IgM antitoxoplasma antibodies in blood from filter papers is less than 1:10000.

The Malmö model: a problem-based learning curriculum in undergraduate dental education

A new undergraduate dental curriculum was introduced in Malmö in 1990 which is based on problem-based learning (PBL). The principles of PBL are strongly influenced by evidence from cognitive psychology and they form the educational strategy throughout the whole curriculum. Two further essential principles underpin the curriculum: a holistic attitude to patient care, and the promotion of oral health. Basic sciences and clinical dentistry are integrated within a structure based on oral conditions prevalent in the community. Students are encouraged to build their new knowledge, understanding and skills into the context of what they have already learned. This approach is facilitated by the presentation of conceptual models, one of which, The Oral Ecosystem is described in detail. The educational programme also gives students opportunities to learn in the clinical context from an early stage, and we endeavour to promote a scientific attitude from the very beginning of the programme. This paper describes the curriculum at three organisational levels (whole curriculum, single course, individual week).

Parental education as viewed by nurses. An interview study

This interview study of nurses in three health centres in Växjö municipality in Sweden sought to find out how they perceived their work with parental education. The aim was to study the possibilities of and any obstacles to achieving the goals of good parenthood training on equal terms for all people. The results showed areas where further development is needed. It appears to be difficult to achieve the goals. Parents' needs for educational measures differed depending on social, cultural, and gender differences. Young single mothers rarely took part in the parents' groups. They belonged to a minority whose needs and problems differed from those of the majority of parents. Also immigrant parents rarely participated in parents' groups. According to the nurses, this may have been due to cultural differences in child care and difficulties with the Swedish language. To give fathers more scope and opportunity to take part, it was suggested that special fathers' groups should be set up. To sum up, families with specific needs should be given more individual education and guidance by nurses. This study, confined to one geographical area, has only shed light on a few nurses' perceptions of parental education, so the findings merely serve to indicate a trend. More general knowledge would require further research-oriented trial projects with the focus on the parents' perspective.

A TCR alpha chain transgene induces maturation of CD4- CD8- alpha beta+ T cells from gamma delta T cell precursors

The proportion of CD4- CD8- double-negative (DN) alpha beta T cells is increased both in the thymus and in peripheral lymphoid organs of TCR alpha chain-transgenic mice. In this report we have characterized this T cell population to elucidate its relationship to alpha beta and gamma delta T cells. We show that the transgenic DN cells are phenotypically similar to gamma delta T cells but distinct from DN NK T cells. The precursors of DN cells have neither rearranged endogenous TCR alpha genes nor been negatively selected by the MIsa antigen, suggesting that they originate from a differentiation stage before the onset of TCR alpha chain rearrangements and CD4/CD8 gene expression. Neither in-frame V delta D delta J delta nor V gamma J gamma rearrangements are over-represented in this population. However, since peripheral gamma delta T cells with functional TCR beta gene rearrangements have been depleted in the transgenics, we propose that the transgenic DN population, at least partially, originates from the precursors of those cells. The present data lend support to the view that maturation signals to gamma delta lineage-committed precursors can be delivered via TCR alpha beta heterodimers.

Self-image, self-values and interpersonal values among newly graduated nurses

This longitudinal study (1994-1996) used the Gordon Personality Inventory to measure nursing students' self-image (Gordon A), self-values (Gordon B) and interpersonal values (Gordon C). It was performed with students from three colleges of health in the south of Sweden: Jönköping (n = 54), Växjö (n = 24) and Kristianstad (n = 38). The null hypothesis of the study was that the new academic three-year programme did not have the power to change significantly the students' self-image and professional values. The hypothesis was tested by paired sample Student's t-test. The result was that, at Jönköping, self-image changed and increased significantly in the dimensions of 'cautiousness' and 'personal relations', and decreased in 'sociability', and increased in the self-value 'order'. At Växjö the self-image dimensions of 'original thinking' and 'personal relations' increased, and, at Kristianstad, the students increased their self-image scores in 'responsibility'.

Direct digital radiography for the detection of periapical bone lesions: a clinical study

The aim was to compare the observer performance of direct digital radiography, with and without image processing, with that of conventional radiography, for the detection of periapical bone lesions. For 50 patients, a conventional periapical radiograph using E-speed film was taken. Then, a direct digital image of the same area was made. The images presenting the periapical bone tissue of 59 roots were assessed by seven observers using a 5-point confidence scale. The digital images were first presented as original images, with default contrast and brightness set by the computer system. Following this, the observers were allowed to use the processing facilities for greyscale treatment. The results for original and processed direct digital images and for conventional radiographs were compared by Receiver Operating Characteristic (ROC) analysis. The area under the ROC curve, calculated as P(A) value, was 0.88 for conventional film, 0.82 for original digital images and 0.78 for processed images. Corresponding Az values were slightly higher, 0.89, 0.84 and 0.81. Statistically significant differences between ROC areas calculated as P(A) values for the methods were found. Comparison between Az values showed no significant differences between conventional radiographs and original digital images, whereas the difference between Az values for original and processed digital images was still significant. It was concluded that conventional film radiography performed slightly better for the detection of periapical bone lesions than direct digital radiography and that image processing did not improve the observer performance.

Endodontic status of mandibular premolars and molars in an adult Swedish population. A longitudinal study 1974-1985

The purpose of the investigation was to study the incidence of endodontic treatment and the progression of periapical disease in an adult Swedish population. A random sample was selected in 1974 and offered a clinical and radiographic examination. In 1985, 345 of the original 1302 persons received a follow-up examination. The present study was based on information obtained from radiographs of the mandibular premolar and molar regions at the two examinations. The highest increase in people with endodontically treated teeth from 1974 to 1985 and the highest increase in people with periapical lesions were found in the youngest age-group, born between 1945 and 1954. New endodontic treatment, received between 1974 and 1985, was mostly found among those who already had endodontically treated teeth in 1974. New periapical lesions also appeared more often in persons with endodontic disorders in 1974.

Follow-up study of endodontic status in an adult Swedish population

The purpose of this study was to examine changes in the endodontic status of selected teeth in a population over time, in order to get a long-term perspective of endodontically treated teeth. A random sample of the adult Swedish population was selected in 1974 and offered a clinical and radiographic examination. Eleven years later 351 of the selected persons attended a follow-up examination (1985). In radiographs, covering the mandibular premolar and molar regions, the status of 1974 was directly compared, tooth by tooth, with the status of 1985. The results showed that a number of endodontically treated teeth with an apical periodontitis healed during the observation period. During the same period, approximately the same number of endodontically treated teeth presented with a new apical periodontitis. This finding suggested that cross-sectional studies could provide reliable information on the long-term success rate of endodontic treatment at the population level. The periapical lesions that persisted or developed during the observation period were strongly related to incomplete root canal obturation, which is in agreement with observations in follow-up studies from teaching and specialist clinics.

Distribution of mercury in rabbits subchronically exposed to low levels of radiolabeled methyl mercury

The metabolism of methyl mercury (MeHg) has been studied in rabbits administered 203Hg-labeled methyl mercuric chloride, 0.125 mumol/kg body weight, twice a week for 9 weeks, by intravenous injection. Twelve weeks after cessation of treatment, about 54% of the administered dose had been excreted in faeces and 5% in urine. After one week, the highest concentration of 203Hg was found in fur (8.6 nmol Hg/g). Substantially lower concentrations were found in kidney (2.5 nmol/g), liver (0.9 nmol/g), brain (0.4 nmol/g), muscle (0.3 nmol/g) and blood (0.1 nmol/g). The rate of elimination of 203Hg from brain, muscle and blood was faster (t1/2 about 12 days) than that from kidney and liver (t1/2 about 28 days). The relative amount of inorganic Hg in kidney and liver increased with time after cessation of treatment. The highest fractions were 85 and 70%, respectively. In brain, no significant demethylation of MeHg could be detected.

Metabolism of methylmercury in rabbits and hamsters

The metabolism of 203Hg-labeled methylmercury chloride (MeHg) has been studied in rabbits and hamsters. Rabbits were administered 1.6 mumols MeHgCl/kg bw intravenously, and hamsters 40 mumols/kg bw orally. Urine and feces were collected daily and groups of four animals killed after 1 h, 1 d, or 7 d. The concentration of 203Hg in blood, liver, kidney, spleen, lung, heart, and brain was determined by gamma counting. In both animal species, the clearance of 203Hg in the brain was slower than in other tissues. In the rabbits the brain 203Hg concentration increased during the whole experimental period. Rabbits excreted 203Hg primarily in feces (about 20% of the dose within 1 wk), and much less in urine (less than 2%). In contrast, hamsters very efficiently excreted 203Hg in urine (50% in 1 wk). The fecal excretion was similar to that of the rabbits. Separation of inorganic Hg and MeHg in urine from hamsters by ion exchange chromatography showed that about 90% of the urinary 203Hg was excreted as MeHg. These findings show that rabbits and hamsters are interesting experimental animal systems for studying the metabolism of MeHg.

Endodontic status and suggested treatment in a population requiring substantial dental care

The purpose of this study was to analyse endodontic status and treatment suggested for Swedish citizens requiring substantial dental care. According to the Swedish dental insurance system, treatment plans including radiographs have to be submitted for approval if the estimated cost of treatment exceeds a certain level (USD 500 in 1977). A sample of 1094 treatment plans received during 1977 and 1978 was randomly selected. In the radiographs the number of remaining teeth was recorded, periapical condition was evaluated and the quantity and quality of previous endodontic treatment were estimated. In addition, treatment plans concerning the teeth with periapical lesions were studied. The results indicated that patients analysed in this study that needed expensive treatment had more missing teeth, more root-filled teeth and more teeth with periapical lesions than what has been reported in previous studies of samples supposed to accurately represent the Swedish population. However, the technical quality of the root fillings and the frequency of periapical lesions in root-filled teeth were the same as in previous studies, with high frequencies of inadequate root fillings and related unfavourable responses. Thus the patients in this study retained a significant need for endodontic treatment despite having already received a great deal of endodontic care. Further, it was found that nearly half of the observed periapical lesions would not be treated based on the submitted plans.

Nocturnal hypoxaemia in severe scoliosis

The relationship between spirometry and daytime blood gases on the one hand and hypoxaemia during sleep on the other was studied in 13 patients with severe thoracic scoliosis. Eight patients had hypoxaemia (mean Sao2 less than 90%) during sleep. They were characterized by a lower vital capacity (30 versus 50% of predicted, P less than 0.01) and by a greater fall in vital capacity from sitting to supine (26 versus 7% of sitting VC, P less than 0.05). All patients with hypoxaemia during sleep were hypercapnic during the daytime. The fall in Sao2 with sleep was related to the increase in transcutaneous PCO2, indicating hypoventilation as the main mechanism behind hypoxaemia during sleep in scoliosis patients.